Thanks for inviting
I don't know about China, but in US,
Yes. it certainly trades in secondary market.
In fact, I trade them all the time.
But it is usually classified a fixed income security, even though it is equity on balance sheet.
You can view them as bonds with $25 par.
So, it trades through fixed income desks, not equity desks.
probably that's why you don't find them in equity exchanges.
In theory, every company could issue preferreds. But in practice, only big Financial Institutions (Banks, Insurance, and capital holding group of big conglomerates(example: GE)) issue preferreds, mainly for regulation reasons (to mask leverage ratio).
A random one for you: